Serotonin 1A-receptor activation suppresses respiratory apneusis in the cat

Neurosci Lett. 1994 May 19;172(1-2):59-62. doi: 10.1016/0304-3940(94)90662-9.

Abstract

Malfunction of inhibitory synaptic processes in the brainstem result in abnormal prolonged inspiration (apneusis). Since we previously found that the serotonin (5-hydroxytryptamine; 5-HT) 5-HT1A receptor agonist 8-hydroxy-dipropylaminotetralin (8-OH-DPAT) shortens inspiratory discharges, we tested its ability to suppress apneusis. We recorded phrenic nerve activity and the membrane potential of medullary expiratory (E-2) and postinspiratory (PI) neurons in 14 anaesthetized, paralyzed, artificially ventilated cats. Systemic hypoxia or i.v. injection of pentobarbital sodium or the N-methyl-D-aspartate (NMDA) receptor blocker ketamine induced apneustic phrenic nerve discharges, delayed depolarization to threshold of E-2 neurons and prolonged hyperpolarization in PI neurons. 8-OH-DPAT (10-40 micrograms/kg i.v.) produced partial to complete restoration of normal phrenic nerve discharges and membrane potential.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / administration & dosage
  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology*
  • Animals
  • Cats
  • Female
  • Hypoxia / physiopathology
  • Injections, Intraventricular
  • Ketamine / antagonists & inhibitors
  • Ketamine / pharmacology
  • Male
  • Membrane Potentials / drug effects
  • Pentobarbital / antagonists & inhibitors
  • Pentobarbital / pharmacology
  • Phrenic Nerve / drug effects
  • Phrenic Nerve / physiopathology
  • Receptors, Serotonin / drug effects
  • Receptors, Serotonin / metabolism*
  • Respiratory Mechanics / drug effects*
  • Synapses / drug effects

Substances

  • Receptors, Serotonin
  • Ketamine
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Pentobarbital